Rock along with your sand IS your "filter" so it's important to have enough of both to do the job we need it to do.

Note: All rock types (Figi, Marshall Island, Caribbean Shelf etc.) will provide homes to good bacteria but some rock types are better suited for building the base reef structure...to ensure it's stable & not always falling! I recommend using Figi (best for shape & price) to build the basic reef structure then feel free to add different rock types for aesthetics, shelving etc. Used in conjunction with the deep sand bed, live rock is the “other half” of Mother Nature’s “natural” biological filtration. Beneficial bacteria lives on & within the rock just like it does on the filter cartridges of your mechanical (let’s say back hanging) power filters, thus eliminating the need for such power filters. Make sure to build your rock structure with a fist size space between your glass & rocks all the way around the tank to allow for good water flow around your rocks. It also creates great swim through places for your fish!

Types of Live Rock:

1. Uncured: This is rock that has not been “cleaned”. When rock is collected from the ocean, some of the living organisms on the rock die during transport. The decomposition process adds excess nutrients to your tank. This is totally acceptable for new tank setups as it will “cycle” your tank. Uncured rock is NOT recommended for established/already harboring livestock tanks.

2. Cured: This is "clean" rock. Any dead organisms are cleaned off the rock & should not add nutrients when placed in your tank. Recommended for established tanks.